We should only vote on occasions in which we have all agreed to be bound by the decision of the majority. The next major U.S. election will take place on November 2016. But, have we all agreed to be bound by its results? Hardly. (Anyone who doubts this should read Lysander Spooner's "No Treason"). In sharp contrast when the chess club votes on whether to meet on Tuesdays or Wednesdays, and all participants have agreed to be bound by the results of the election, then this is a valid one.
As for stereotyping, that's merely making broad empirical generalizations, or engaging in induction. Induction, along with deduction, are two pillars of the scientific outlook. We as libertarians should reject it holus bolus? There is nothing wrong with stereotyping, let alone anything incompatible with libertarianism in that mode of thinking. For example, Men are taller and stronger than women (on average). Whites are better swimmers than blacks; blacks are better runners and jumpers than whites (on average). Child novelists are very rare. Old people are more likely to contract cancer and Alzheimer's disease than young people; the opposites rarely occur. Ceteris paribus, gays have higher time preference rates than straights (Hans Hoppe got in trouble with the politically correct academics at his school, UNLV, for saying this); heterosexuals tend to have more children than homosexuals, and thus have, again on average, a longer time horizon. These are all stereotypes. They are all correct empirical generalizations. Their opposites are also stereotypes, but incorrect ones.
The libertarian opposition to collectivism is a vestige of Ayn Rand's in some ways baleful influence on our libertarian movement. There is nothing wrong with collectivism, nor is there anything incompatible with libertarianism in it. Team sports are collective efforts; individual sports are based on individualism: individual efforts. Are libertarians supposed to be against team sports? Should we ban them? A barn-raising is a collective action. Chopping wood is usually done individually. Chess playing is a collective effort; the card game, Solitaire, is played by only one person. Should the former set of activities be banned by libertarian law? That notion is silly.